1. Field of the Invention
The present invention relates to an arrangement for a consecutive two-stage ejector of the built-in type for moulding tools comprising pairs of moving ejector plates and an actuating device for causing the aforementioned ejector plates to be moved to intended positions.
2. Description of Related Art
Previously disclosed consecutive two-stage ejectors of the kind that are intended for building-in are designed as a rule so that they exhibit a highly advanced actuating device, which is positioned on the front pair of ejector plates. This actuating device is formed by two half moonshaped rings that are produced by wire spark erosion, which is a very time-consuming production process. The previously disclosed two-stage ejectors must also be secured against rotation with rotation-preventing means, which increases the cost.
The principal object of the present invention is, in the first instance, to solve the aforementioned problems by simple and reliably functioning means in conjunction with a moulding machine essentially for the manufacture of plastic components, but also for metal-forming tools, and to achieve a solution that is simple to produce, cost-effective and reliable in service.
The aforementioned object is achieved by means of an arrangement in accordance with the present invention, which is characterized essentially
in that rear ejector plates are attached to, and are capable of actuation by, a reciprocating rod that is connected to the tool,
in that a central pin extends between the fixed plate of the moulding tool and the body of the moulding tool,
in that the aforementioned central pin exhibits an annular groove,
in that pairs of sleeves are accommodated by the aforementioned central pin with one sleeve passed onto the other sleeve,
in that each of the two sleeves is attached to its own moving ejector plate,
in that the inner sleeve exhibits transcurrent recesses corresponding to the desired number of locking segments,
in that the outer sleeve exhibits a stop part capable of actuating the aforementioned locking segment,
in that the aforementioned locking segments exhibit stop parts capable of interacting with the aforementioned grooves,
in that the two ejector plates are attached to one another via an attachment which permits free packing together of the aforementioned pairs of ejector plates, which are retracted to a specified distance from one another, when the aforementioned rear pair of plates is caused respectively to be extended and retracted, in conjunction with which the ejector of the tool is so arranged in an initial phase as to actuate the rear ejector plates and so that the front ejector plates are conveyed along through the interconnection of the two sleeves with the help of the locking segments, and in that, after actuation of the locking segments and their accommodation in the aforementioned annular groove, the front ejector plates are released and the rear ejector plates are so arranged as to be actuated singly by the ejector causing them to be extended to the intended end position.